On January 31, 1968, the first day of the celebration of the lunar new year, Vietnam's most important holiday, the North launched a major offensive throughout South Vietnam. This was known as the Tet Offensive. It took weeks for U.S. and South Vietnamese troops to retake all of the captured cities, including the former capital of Hue. Although the offensive was not militarily successful for the Vietnamese Communists and did not meet its major objectives, it was a political and psychological victory for them. It significantly contradicted optimistic claims by the U.S. government that the war had already been won.
For the average US citizen the Tet Offensive provided the dramatic realization that the war in Vietnam was futile. They were being told that the war was near an end and that they were close to victory. Their own President had told them that the US and her allies were now winning the war and that "There's a light at the end of the tunnel."
But with the media coverage of the Tet Offensive they suddenly saw a very different picture of the war - a determined and so far unbeaten enemy. The Viet Cong were seen taking over the American Embassy in Saigon and at first, the offensive seemed like a devastating blow to the Americans and the South.
People started to question the motives of the US in Vietnam and started to ask whether a war against such passionate opponents could ever be won.
Because of this change in public opinion the Tet Offensive was one of the reasons for the withdrawal of American troops in Vietnam, and the decline in US involvement. Without the enthusiasm of the general public the US government could not keep pouring money into the Vietnamese military budget (it had...